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How do multii-speed fans in new OIL warm air furnaces work. One
webpage said that such a fan might use 200 watts, but the one speed
fan my current furnace has might use 800 watts! That seems amazing.

It also gave the impression that when the furnace calls for the low
speed fan, it's because the fan runs all the time. Is that right?

I'm used to the idea that very few oil furnaces have efficiency 90% or
greater, and that they are very expensive. But if I get a
electronically controlled fan with the furnace, that part of the
furnace is eligible for the Federal Energy Credit, and I presume it's
something I want to have anyhow. But I'd like to know how it works
before I buy one.

On 10/17/2010 7:51 AM, Don Phillipson wrote:
wrote in message
...
Do low-speed fans on new warm air oil furnaces run all the time?

Furnace fans are commonly controlled by thermostat switches
with three settings:
Off = fan never runs
On = fan runs always
Automatic = fan runs when required by the heating unit.

Newer stuff with DC drive motors for the air handler may run at a
very low speed continuously to even out the temperature of the home.
The first HVAC system I came across with this feature had me thinking
there was something wrong until I called the supplier and was assured
it was a normal operating mode. The best bet is to call the manufacturer
and find out if the continuous low speed is a feature of your new gear.

mm wrote:
Do low-speed fans on new warm air oil furnaces run all the time?

How do multii-speed fans in new OIL warm air furnaces work. One
webpage said that such a fan might use 200 watts, but the one speed
fan my current furnace has might use 800 watts! That seems amazing.

It also gave the impression that when the furnace calls for the low
speed fan, it's because the fan runs all the time. Is that right?

I'm used to the idea that very few oil furnaces have efficiency 90% or
greater, and that they are very expensive. But if I get a
electronically controlled fan with the furnace, that part of the
furnace is eligible for the Federal Energy Credit, and I presume it's
something I want to have anyhow. But I'd like to know how it works
before I buy one.

Our furnace has a continuously variable DC fan that is (as far as I know)
always running. You set your thermostat fan control to "ON" and the
computer manages the speed.

When not calling for heating or cooling the fan runs very slowly. You might
feel a slight draft from the vent, but you could never hear it running.
This was explained as helping to "even out" the temperatures within the
home.

On 10/17/2010 10:06 AM, Rick Brandt wrote:
mm wrote:
Do low-speed fans on new warm air oil furnaces run all the time?

How do multii-speed fans in new OIL warm air furnaces work. One
webpage said that such a fan might use 200 watts, but the one speed
fan my current furnace has might use 800 watts! That seems amazing.

It also gave the impression that when the furnace calls for the low
speed fan, it's because the fan runs all the time. Is that right?

I'm used to the idea that very few oil furnaces have efficiency 90% or
greater, and that they are very expensive. But if I get a
electronically controlled fan with the furnace, that part of the
furnace is eligible for the Federal Energy Credit, and I presume it's
something I want to have anyhow. But I'd like to know how it works
before I buy one.

Our furnace has a continuously variable DC fan that is (as far as I know)
always running. You set your thermostat fan control to "ON" and the
computer manages the speed.

When not calling for heating or cooling the fan runs very slowly. You might
feel a slight draft from the vent, but you could never hear it running.
This was explained as helping to "even out" the temperatures within the
home.

I have a new furnace (Amana) with the Electronically Commutated Motor
(ECM) inside blower. I know it doesn't run all the time. You can
select continuous run on the thermostat. Also, there are different
"programmable" features done my the HVAC guy like ramp up, ramp down,
etc. I don't know if they can program any kind of constant run or not,
but it probably depends on the brand.

On 10/17/2010 1:12 AM, mm wrote:
Do low-speed fans on new warm air oil furnaces run all the time?

How do multii-speed fans in new OIL warm air furnaces work. One
webpage said that such a fan might use 200 watts, but the one speed
fan my current furnace has might use 800 watts! That seems amazing.

It also gave the impression that when the furnace calls for the low
speed fan, it's because the fan runs all the time. Is that right?

I'm used to the idea that very few oil furnaces have efficiency 90% or
greater, and that they are very expensive. But if I get a
electronically controlled fan with the furnace, that part of the
furnace is eligible for the Federal Energy Credit, and I presume it's
something I want to have anyhow. But I'd like to know how it works
before I buy one.

Thanks.

I believe mine runs at two speeds, high and low.
Wife is constantly complaining that it is not as warm even though
thermostat is constant, you just don't get that blast of warm air.
Told her she is welcome to turn up the heat but at $3+ per gallon she is
reticent to do so

On Sun, 17 Oct 2010 08:51:08 -0400, "Don Phillipson"
wrote:
"mm" wrote in message
.. .
Do low-speed fans on new warm air oil furnaces run all the time?

Furnace fans are commonly controlled by thermostat switches
with three settings:
Off = fan never runs
On = fan runs always
Automatic = fan runs when required by the heating unit.
And the VAST majority of new furnace installations DO run the fan at
low speed constantly when on "automatic" - kicking up to higher speeds
when heat or cooling are called for.
In most cases, AC blower is higher than heat blower speed.

On Sun, 17 Oct 2010 08:22:54 -0500, The Daring Dufas
wrote:
On 10/17/2010 7:51 AM, Don Phillipson wrote:
wrote in message
...
Do low-speed fans on new warm air oil furnaces run all the time?

Furnace fans are commonly controlled by thermostat switches
with three settings:
Off = fan never runs
On = fan runs always
Automatic = fan runs when required by the heating unit.

Newer stuff with DC drive motors for the air handler may run at a
very low speed continuously to even out the temperature of the home.
The first HVAC system I came across with this feature had me thinking
there was something wrong until I called the supplier and was assured
it was a normal operating mode. The best bet is to call the manufacturer
and find out if the continuous low speed is a feature of your new gear.

TDD
It is an available setting on virtually all currently available forced
air furnaces - and ALL DC variable speed systems.

On Sun, 17 Oct 2010 09:06:26 -0500, Rick Brandt
wrote:
mm wrote:
Do low-speed fans on new warm air oil furnaces run all the time?

How do multii-speed fans in new OIL warm air furnaces work. One
webpage said that such a fan might use 200 watts, but the one speed
fan my current furnace has might use 800 watts! That seems amazing.

It also gave the impression that when the furnace calls for the low
speed fan, it's because the fan runs all the time. Is that right?

I'm used to the idea that very few oil furnaces have efficiency 90% or
greater, and that they are very expensive. But if I get a
electronically controlled fan with the furnace, that part of the
furnace is eligible for the Federal Energy Credit, and I presume it's
something I want to have anyhow. But I'd like to know how it works
before I buy one.

Our furnace has a continuously variable DC fan that is (as far as I know)
always running. You set your thermostat fan control to "ON" and the
computer manages the speed.

Does that mean if you set it to auto, it would go off when the furnace
isn't running? I like the feature you describe if I'm not stuck using
it when I don't want to.
When not calling for heating or cooling the fan runs very slowly. You might
feel a slight draft from the vent, but you could never hear it running.

I'm afraid I might. It is a straight shot from the furnace to the big
vent in the hall right outside the bedroom door, and the noise of my
current fan has been a big problem. I tried changing the fixed speed
on my fan, by connecting different wires, but as the schematic said,
it was already on the lowest speed. I have to shut the door when I'm
sleeping or trying to get to sleep.
This was explained as helping to "even out" the temperatures within the
home.